System for providing video on demand with pause feature

ABSTRACT

A system for providing video upon request may transmit encrypted video information to one or more recipients for viewing at a later time. The recipient may make a request to view one of the received video files. This request may be provided to a video transmitter which may provide, in return, video decryption information to allow immediate viewing of the previously received video transmission.

BACKGROUND

This invention relates generally to providing video information to aplurality of users in a video distribution system.

Current video distribution systems include pay per view systems whichare available from cable and satellite television providers. In thesesystems, a variety of different pay per view movies are offered forviewing at a plurality of different times. The user must either join thevideo in progress or wait until a preset time when a new video begins.By offering a plurality of different starting times, these systemsattempt to provide an approximation of video on demand.

In order to provide the video to a plurality of users at the exact timeswhen they would like to have it, one might expect that a large bandwidthwould be necessary. That is, given a large number of viewers, it wouldseem to be difficult to transmit different videos at a plurality oftimes given the bandwidth available with existing satellite and cablevideo distribution systems.

This means that the system users must accommodate their viewing desiresto the existing bandwidth limitations of the video distribution system.Where those viewing desires do not correspond with the capabilities ofexisting systems, potential customers are lost.

Thus, it would desirable to provide a video distribution system whichpermits video distribution upon demand from the user.

SUMMARY

In accordance with one embodiment, a receiver for receiving videoinformation from a video transmitter includes a storage medium forstoring video information received by the receiver. A decryption engineis adapted to decrypt the stored video information. A controller isadapted to control the video storage medium and the decryption engineand to request decryption information for the engine.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic depiction of a video distribution network inaccordance with one embodiment of the present invention;

FIG. 2 shows a flow chart for implementing a receiver in accordance withthe system shown in FIG. 1; and

FIG. 3 is a block diagram showing one system for implementing thereceiver shown in FIG. 1.

DETAILED DESCRIPTION

Referring to FIG. 1, a video distribution system 10 may be implementedin a variety of different video distribution environments includingcable, television broadcast, or satellite as examples. The videoprovider 14, which may be a cable provider or a satellite systemprovider as examples, transmits video, as indicated at 16, to aplurality of receivers 12 which may be processor based televisionreceivers. The processor based television receivers may, for example, beso called set-top computer systems which use a television receiver as adisplay. Alternatively other computer systems and appliances may be usedas well.

Instead of transmitting the video at a set or predetermined timecorresponding to the time the video will be viewed, the video may becontinually or semi-continuously streamed to all of the receivers in anencrypted form. Alternatively the video may simply be transmitted inadvance and stored on a plurality of receivers. The individual receivers12 may not be capable (without additional information) of displaying thetransmitted video information. Thus, to the extent possible given thebandwidth of the system, video may be transmitted to the receiver 12 andstored thereon, for example in a memory 22, for viewing at a later time.

When a user desires to view particular video information, such as amovie, at any time, the user may simply request the decryptioninformation, for example, from the video provider 14. In a two-waytransmission scheme the request for decryption information may betransmitted over the same transport that conveyed the video.Alternatively, a separate medium or channel may be used. In addition,the decryption information may be requested from a source different fromthe video provider 14, in one embodiment of the invention.

The decryption information may then be transmitted with unrelated videoinformation 16, in one example, to the receiver 12. For example, undercontrol by the controller 15, the decryption information may be providedtogether with information about the intended recipient. Equipped withthe decryption key for a particular video such as a movie, the receiver12 can decrypt the video and allow the viewer to view the video ondemand.

Where each of the receivers 12 includes a unique identifier and thedecryption information is coded for the requesting receiver, only thereceiver whose identifier matches an identifier transmitted with thedecryption key is able to decode the decryption key for the requestedvideo. In addition, when the receiver requests the decryptioninformation, the receiver may not only be provided the decryptioninformation, but appropriate billing provisions may be implemented aswell.

Requests for the decryption information may be provided through atelephone network 20 as one example. As another example, the request maybe made over an electronic network, such as the Internet usingelectronic mail. Thus, in effect a back channel may be used to requestthe decryption information from the video provider or other source inone embodiment. The video provider (or other source) then may providenot only the decryption information, but in one embodiment of theinvention, the information needed to access the receiver's memory forthe selected video information may also be provided. This accessinformation may be provided as script or other software.

A predetermined amount of storage may be devoted to storing the videotransmissions. When the video transmissions transmitted to a givenreceiver exceed the amount of dedicated storage, the oldest informationmay be deleted in order to make room to store the most recently receivedinformation. Alternatively, the video provider 14 may provide a signaleach time it sends a new video to discard a particular video previouslystored on a given receiver 12.

Since the video may be transmitted to the receiver 12, ahead of theviewing time, in one example, bandwidth limitations may be overcome.That is, the need to transmit a plurality of large video files at thesame time to satisfy the demands of a large number of users is notnecessary. Instead a set of video transmissions are streamed to all orpart of a group of receivers which store those transmissions for laterrecall.

Referring now to FIG. 2, software, in accordance with one embodiment,may be stored on the receiver 12 for implementing a video on demandsystem. The software 26 may begin by receiving and storing the encryptedvideo as indicated in block 28. In one embodiment, this may be done atparticular times when volume in the transmission channel is low or thetransmission may be done continuously or semi-continuously so as tostore a library of video files on the receiver 12.

Upon request for video, as indicated in diamond 30, the receiver 12requests a decryption key as indicated in block 32. This request may becarried over a back channel, in one embodiment of the invention, througha network 20 such as the Internet or a telephone network. Next, thevideo, stored in an encrypted form on the receiver 12, is retrieved asindicated in block 34. The video may then be automatically decrypted asindicated in block 36, and the display of the video may begin asindicated in block 38.

Generally, it may be desirable to transmit a decryption key for sectionsor portions of a given video. Thus, to view the entire video, thereceiver must receive one or more video decryption keys, each of whichmay be used to decrypt a portion (less than all) of the videoinformation. The advantage of this technique is that a pirate mustobtain a number of video decryption keys in order to decrypt the entirevideo. This makes it harder to pirate the decryption keys, decreasingthe likelihood of theft of services. For example, a new decryption keymay be needed for each minute of video. Therefore, it may be desirableto transmit a new decryption key every minute, once an initial requestfor decryption information has been made.

If the user wishes to pause the ongoing video transmission (diamond 40),a signal may be sent, for example, over a back channel to the videoprovider 14 requesting a pause authorization (block 42). The videoprovider may respond by providing an acknowledgement number (block 44).When the user wishes to resume the video transmission, the user maysimply press a “resume” key and provide the acknowledgement number. Thevideo provider then knows when the particular receiver paused andprovides the appropriate keys to allow the user to continue to view therest of the video that was already requested, and presumably, billed.

Turning now to FIG. 3, an example of a system that may be used as areceiver 12 is illustrated. The receiver 12 may include a processor 65coupled to an accelerated graphics port (AGP) chipset 66. TheAccelerated Graphics Port Specification, Rev 2.0, is available fromIntel Corporation of Santa Clara, Calif. The chipset 66 may be coupledto system memory 68 and the accelerated graphics port bus 70. The bus 70in turn may be coupled to a graphics accelerator 72, also coupled to avideo or television receiver 73.

The chipset 66 may also be coupled to a bus 74 that receives a TVtuner/capture card 76. The card 76 may be coupled to a televisionantenna 78 which may also be a satellite antenna or a cable connectionas additional examples. A connection to a network 90, such as a modemconnection to the Internet or a network controller connection to acomputer network may also be provided.

The bus 74 is coupled to a bridge 80 which in turn is coupled to a harddisk drive 82. The hard disk drive 82 may store the software 26 and 46.The software 100 may be script transmitted from the transmitter 14 toassist in locating stored video information.

The bridge 80 may in turn be coupled to another bus 84 which supports aserial output interface 86 and a BIOS 94. The interface 86 may becoupled to a modem 92 or a mouse 88.

While the present invention has been described with respect to a limitednumber of embodiments, those skilled in the art will appreciate numerousmodifications and variations therefrom. It is intended that the appendedclaims cover all such modifications and variations which fall within thetrue spirit and scope of the present invention.

What is claimed is:
 1. A receiver device for receiving video informationfrom a video transmitter comprising: a storage medium for storing videoinformation received by a receiver the device; a decryption engine todecrypt stored video information; and a controller processor to controlthe storage medium and the decryption engine and request decryptioninformation for the engine, said controller processor to control theplay of video, to receive a request to pause the play of said video andto automatically request a code to enable video play to be resumed at alater time.
 2. The receiver of claim 1 wherein said controller includesa processor.
 3. The receiver device of claim 1 wherein said engine isadopted adapted to decrypt stored video upon receipt of a request toview stored video.
 4. A video transmission system comprising: a videotransmitter that transmits video to a plurality of receivers for displayat a later time; and a controller that transmits decryption informationto said receivers to enable video upon request, said controller receivesa request for a code to enable the play of video to be paused and to beresumed at a later time, and in response said controller automaticallyprovides said code.
 5. The system of claim 4 wherein said controlleralso is adapted to transmit an identifier which identifies a particularreceiver to receive said decryption information.
 6. The system of claim5 wherein said controller is part of said transmitter.
 7. The system ofclaim 4 wherein said video transmitter transmits video over a cablesystem.
 8. The system of claim 4 wherein said video transmittertransmits video over a satellite system.
 9. The system of claim 4wherein said transmitter also transmits information to assist inlocating particular video files transmitted by said transmitter to saidreceivers.
 10. A method comprising: storing encrypted video in areceiver; requesting a decryption key for said stored video; playingsaid video; receiving a request to pause said play of video;automatically requesting a code to enable said video to be played at alater time; and receiving an acknowledgement code and using saidacknowledgement code to resume the play of video.
 11. The method ofclaim 10 including receiving the encrypted video from one source andreceiving the decryption key from a second source.
 12. The method ofclaim 10 including receiving the video and said decryption key from thesame source.
 13. The method of claim 10 including receiving anidentifier to identify a particular receiver to receive said key. 14.The method of claim 10 wherein using said acknowledgement numberincludes using said acknowledgement number to resume the play of videowithout an additional charge.
 15. A video distribution methodcomprising: storing video for selection by the recipient; upon requestby the recipient, allowing the recipient to select for viewing a storedvideo; playing said video; in response to a request to pause the play ofsaid video, automatically requesting a code to enable play to be resumedat a later time; and enabling the user to press a button to resume theplay of said video and in response to the operation of said button,automatically transmitting a code to enable resumed play of said video.16. The method of claim 15 including providing a graphical userinterface which displays the video information which is available forselection by the user.
 17. The method of claim 15 further includingreceiving a key to enable decryption of the video.
 18. The method ofclaim 17 including resuming the play of video from the point where thevideo play was paused.
 19. An article comprising a non-transitory mediumfor storing instructions that cause a processor based system to: storevideo for selection by the recipient; upon request by a recipient, allowthe recipient to select, for viewing, video previously stored; play saidvideo; and in response to a request to pause the play of said video,automatically request a code to enable play to be resumed at a latertime.
 20. An article comprising a non-transitory medium for storinginstructions that cause a processor based system to: store encryptedvideo to a receiver; request a decryption key, for said stored video;play said video; receive a request to pause said play of video; andautomatically request a code to enable said video to be played at alater time.
 21. The article of claim 20 including instructions thatcause a processor based system to receive the encrypted video from onesource and receive the decryption key from a second source.
 22. Thearticle of claim 20 including instructions that cause a processor basedsystem to receive the video and said decryption key from the samesource.
 23. The article of claim 20 including instructions that cause aprocessor based system to receive an identifier to identify a particularreceiver to receive said key.